How can I change the circuit from NiCd charging for use with alkaline batteries in a ALGE S4 timer? Somebody can help me? thank´s

The S4 has a small window located next to the ON/OFF rocker switch on the back. The timer is set for NICAD battery use IF the red jumper is visible. It is set for ALKALINE battery use if it not visible.

Remove the Phillips #1 screws from both ends of the timer.

Lift the top cover off.

Move the red jumper located in the back corner of the main circuit board next to the rocker switch using tweezers or small needle nose pliers.

The external charger can still be used with ALKALINES so long as that jumper is moved.

There is a small sticker next to the battery box cover. Alter that to reflect the new status as well.

Replace screws and test.

OK thank you FKP. I do it, and work perfect, but can I use alkaline and the external charge at the same time (the batteries remain as backup)?

Yes